VGAtoRJ45conversion

From ElephantStaircase

Contents

Summary

A VGA monitor connection only requires 8 conductors for operations. Although it has many pins, they are not all needed, and some are used for keying. An Ethernet cable (CAT5, CAT5e, CAT6) cable has 8 conductors and can carry the signal a long distance on a thin cable for cheap.

Motivation

I was just about to finish my projector project when I hit a snag. I needed a super long VGA cable to reach from the LCD to my computer, which were on opposite sides of the room. Initially I was going to move my computer to the projector but decided against it. I read a few articles involved with VGA conversion and decided to give it a shotter. Of course it might have been more practical to buy an extra long VGA cord for around $25 plus shipping, albeit more expensive.

Introduction

I’ve been working to extend audio and video signals with a few different projects so far, first was the RCA cable to CAT5 conversion boxes. I always feel constrained by the cords I use for all my electronics. I came up with the idea after watching a movie in my dorm room. Although I have a decently sized room, I don’t have a huge monitor, only a 17” LCD. Even with a little rearranging on my desk, it still impossible to get it close enough for my viewing pleasure. The cords are just not long enough. I figured if I patch the VGA across a CAT5 cable (since I have a lot of it), I can just unplug the monitor and plug it in where ever I want in my room. I’ll just have to deal with some long cords running across my room while I watch the movie, a minor inconvenience.

The conversion isn’t to hard if you can find the right materials. A good RJ45 (Ethernet conversion box) is essential. The only soldering you have to do is 8 connection pins to the VGA port (twice, of course).

What you'll need

Part

Cost/Unit

QTY

Total

Link

RJ45 project box

$2

2

$4

--

VGA connector port

$0.50

2

$1

--

4 inch colored wire

$0.50/ft

1ft

$0.50

--

VGA cable

**

**

--

--

Ethernet cable

**

**

--

--

Epoxy

$2

1

$2

--

Soldering iron

$25

1

$25

--

Solder

$4

1

$4

--

Dremel or drill

$60

1

$60

--

Total

~$8

--

--

--

** - dependant upon length
Total assume you already have big ticket items as I can't imagine going out and buying a dremel for this project alone.

For an easier project:
. Here is an item that would make this project mucho easier, less expensive and time consuming. Male HD15 to RJ45 Adapter: Adapter - 79 cents. All you'd need is two of these, your CAT5 cable and perhaps a gender changer for one end or the other. Some individuals have not had success with this particular product - it may not be a valid alternative to making your own.

Steps

1. Cut and prep wires – You will need 16 wires 22 gauge recommended, any bigger and it will be difficult to solder. USE DIFFERENT COLOURS. I can’t stress that enough, it will make your life a lot easier when matching up which wire goes to which connection. Cut the wires roughly 4 inches in length, stripping one end of each by a few millimeters.

2. Prep the boxes – Take a look at inside of your RJ45 box. They are not all the same, but they are similar. Find a good spot to put the VGA port that won’t interfere with any screws, RJ45 connections, and will have enough space to fit 8 wires. Use a dremel or drill to cut a hole to fit the VGA port. Make sure size it right, you don’t want it to fall through. Dry fit the piece a few times before you are confident that it will work, looks clean, and won’t interfere with anything.

3. Soldering wires to the VGA ports – on the reverse side of the VGA ports, there are pins to solder wires to. You only have to solder 8 different ones so don’t worry

4. Connecting VGA wires to RJ45 inputs -- Here is a chart that I used from this site that will show you which wires to connect to which pins.

I don’t know if it is absolutely important to use the specific leads for the individual VGA signals. It makes sense that you’d won’t to keep the twisted pairs in mind while you do it. The connection process is very simple. Just lay the wire across the intended connection tract and press the small connector block will it snaps into place. I recommend pressing each wire in place one at a time to secure them, so there is no movement when trying secure other wires. The connector block can be removed upon snapping it down so don’t worry, not permanent. Here you can see the block over a wire resting in a tract that is ready to be snapped into place. Make sure to run the wires through the VGA hole first!!

Completed Projects

5. Mount the VGA port – When you are confident in you’re connections and soldering….this may involve checking each connection with a multi-meter, or just blind faith, mount the VGA ports to the box. I used epoxy since I was too cheap to use the usual screws. After that you are done. Screw the box back together and test it out.

I didn't use project boxes for my adaptors, I used 2 RJ45 wall-jacks, one male and one female VGA connector. I followed the same steps as the instructions and I have great results! I tested my adaptors by having both monitors display first a black and white background and second a high color background. I first tested my adaptors with a 5 foot cat5e patch cable. I didn't even notice a difference between the two monitors. The next test I decided to run the full test and step up to my 100' cat5 cable. I noticed some ghosting now, very light hard to notice. Also when I turn my frequency up it starts to flicker but, 85hz is plenty. My total cost was zero since I had all the parts laying around already. I am probably going to make one improvement though, I plan on switching over to shielded RJ45 Jacks and cable (which I also have laying around). All in all I would say that it works great! - Jason

I saved much money on VGA cables by using UTP instead. I just tested it and it goes up to 20m without visible ghosting.
30+ meters is possible if you use FTP/STP and grounded metal boxes.
I soldered the wires directly to the RJ-45 connector and that's something you shouldn't try unless you have a clean surface such as an attached PCB.

Sources and inspiration

This site helped me out with the pinouts, especially with the diagram…very pretty, thanks a lot.

Further Ideas

The next piece of the puzzle is a VGA switch box. I know you can buy them for not to much but I am toying with the idea of building one…it would just require the right switch knob. Something similar to the RCASwitchBox would be the plan. If I don’t do it for this project I would do it for my speaker set up, switching one control pod back and forth between two systems.